Chateaubriand beef filet with mustard & mayo sauce

For sauce: 

Clean the chili peppers using kitchen or latex gloves to prevent skin irritations.

Finely chop 1 chili pepper and put aside. Cut the other chili peppers in larger pieces and put them into the blender.

Add Mustard & Mayo dressing, olive oil and mix well the ingredients for about 30 seconds, until a creamy, smooth sauce is made.

Transfer in a medium bowl, add fresh spring onions, salt, pepper and mix well.

Cover the bowl with a plastic wrap and put in the refrigerator until served.

For filet:

Salt and pepper the filet on both sides.

In a big non-stick pan, preferably with ribbed bottom, put olive oil and butter to warm with high heat, to burn well.

Place the chateaubriand filets in the pan and cook them for 2 – 4 minutes (rare to medium), without turning them to develop nice ribbed lines.

Carefully turn them with a wooden spatula and cook them for 2 – 4 minutes, until browned.

For well-done extent cooking for 1 – 2 minutes more, each side.

Let the filets rest for 4 – 5 minutes and divide in plates. Sprinkle 1- 2 tablespoons sauce in every dish and serve immediately.